The present disclosure relates to a display device, and to a technique applicable to a display device including a touch panel in the inside of the display device, for example.
A liquid crystal display device has a liquid crystal display panel, and the liquid crystal display panel has a configuration in which a liquid crystal composition is encapsulated between two substrates. Moreover, such a liquid crystal display device is mass-produced in which a touch panel is disposed as an input device on the front face of the liquid crystal display panel. Such a liquid crystal display device is proposed in which a change in capacitance or in a resistance value is used for detecting an input to the touch panel (in the following, referred to as a touch).
The touch panel that detects a change in the electrostatic capacitance is one that detects a change in the electrostatic capacitance between two electrodes disposed through an insulating film, which is referred to as an electrostatic capacitive touch panel below. In the electrostatic capacitive touch panel, a so-called in cell type display panel is proposed in which a common electrode (a counter electrode) for display originally provided on the display panel is also used for one of a pair of touch sensor electrodes and the other electrode (a touch detecting electrode) is disposed so as to cross this common electrode.
It is noted that when prior art search was performed after the present invention was made, Japanese Unexamined Patent Application Publication No. 2012-230657, Japanese Unexamined Patent Application Publication No. 2012-221485, and US Patent Application Publication No. 2012/0262387 were extracted as related techniques. Japanese Unexamined Patent Application Publication No. 2012-230657 is an application that claims priority. Japanese Unexamined Patent Application Publication No. 2012-221485 is a divisional application. Both techniques have the same original patent application. Moreover, US Patent Application Publication No. 2012/0262387 is an application that claims priority under the Paris Convention whose basic applications are the original patent application of Japanese Unexamined Patent Application Publication No. 2012-230657 (the original patent application of Japanese Unexamined Patent Application Publication No. 2012-221485) and Japanese Unexamined Patent Application Publication No. 2012-230657. Japanese Unexamined Patent Application Publication No. 2012-230657 discloses that a display device is provided with a touch detecting function and a driver for a drive signal drive electrode is formed on a TFT substrate using a TFT element to supply two direct current drive signals to the drive electrode of the display device. Japanese Unexamined Patent Application Publication No. 2012-221485 discloses a driver for a drive signal drive electrode that supplies an alternating current drive signal and a direct current drive signal to the drive electrode of a display device provided with a touch detecting function.